1. Field of the Invention
The present invention relates to a scroll compressor used for a refrigerating machine, an air conditioner and the like.
2. Description of the Related Art
FIG. 5 shows a longitudinal sectional view of a compression mechanism part of a conventional scroll type refrigerant compressor disclosed in Japanese Unexamined Patent Publication No. 2000-337276. In FIG. 5, a fixed scroll 1, a seat 1a of the fixed scroll 1, a spiral blade 1b of the fixed scroll 1, an orbiting scroll 2, a seat 2a of the orbiting scroll 2, and a spiral blade 2b of the orbiting scroll 2 are provided. An orbiting bearing 2c is provided at a central part of the surface of the orbiting scroll opposite to the surface where the spiral blade 2b of the orbiting scroll 2 exists. A thrust surface 2d is formed on the end of the surface where the orbiting bearing 2c is provided. The orbiting scroll 2 is connected with an eccentric part 4a of a main shaft 4 through the orbiting bearing 2c. The eccentric part 4a is off-center by r shown in FIG. 5 with respect to the center line of the main shaft 4, and the amount of r is specified by the following formula.
r=1/2Pxe2x88x921/2(To+Tf)
P: spiral pitch (distance between blade sides),
To: spiral blade thickness of orbiting scroll
Tf: spiral blade thickness of fixed scroll
The orbiting scroll 2 executes an orbiting motion to the fixed scroll 1 based on a rotation of the main shaft 4 and a rotation suppression by an Oldham coupling 6, which causes a fluid compression. The main shaft 4 is supported in the radial direction by a main bearing 3b having a sliding member between the main bearing 3b and a compliant frame 3.
A rotor 8 is fitted and engaged with the main shaft 4, and the main shaft 4 is driven by a motor rotation based on the rotor 8 and a stator 9. There is a space 10 between an external diameter 8a of the rotor 8 and an internal diameter 9a of the stator 9 in order to avoid the rotor 8 contacting the stator 9 during the rotation. A thrust surface 3a is formed on the compliant frame 3 which supports a thrust surface 2d of the orbiting scroll 2 in the axial direction. The compliant frame 3 supports a main shaft load generated during operation, at the main bearing 3b in the direction of radius. In order to support the load at a guide frame 5, an upper fitting surface 3c and a lower fitting surface 3d are formed on the compliant frame 3. The upper fitting surface 3c is fitted and engaged with an upper fitting surface 5a of the guide frame 5 in the radial direction with having a minute space, and the lower fitting surface 3d is fitted and engaged with a lower fitting surface 5b in the radial direction with having a minute space. The clearances (spaces) at the upper fitting surface and the lower fitting surface between the compliant frame and the guide frame are set to be almost equal.
With respect to the radial direction, the compliant frame 3 in operation moves in the direction of a load which the main bearing receives from the main shaft, by the amount of the clearance. The upper fitting surface 3c of the compliant frame 3 contacts the upper fitting surface 5a of the guide frame 5 in the load direction of the main bearing, and the lower fitting surface 3d of the compliant frame 3 contacts the lower fitting surface 5b of the guide frame 5 in the load direction of the main bearing. As the load direction of the main bearing continuously changes 360 degrees during one rotation, the compliant frame 3 performs a minute orbiting motion in the guide frame 5. In addition, as the compliant frame 3 shifts in the radial direction, the space 10 between the rotor and the stator is reduced by the amount of the shifting.
In the conventional scroll compressor, as stated above, the upper fitting surface 3c and the lower fitting surface 3d are formed on the compliant frame 3, and each of the upper fitting surface 3c and the lower fitting surface 3d is fitted and engaged with the upper fitting surface 5a or the lower fitting surface 5b on the guide frame 5, with having a space in the direction of radius. Then, the compliant frame 3 moves in the direction of the load received from the main bearing, by the amount of the space. Relating to this movement, the orbiting scroll interlocked through the main shaft and the bearing, also moves in the direction of radius. According as the compliant frame moves, the orbiting scroll moves by the amount of a clearance from the original rotation center, a side space between the swirl of the orbiting scroll and the swirl of the fixed scroll is extended. As the swirl of the orbiting scroll makes the side space extend with respect to the swirl of the fixed scroll, a leak from the swirl side in the scroll compression chamber is increased, which causes performance deterioration. Further, as the compliant frame 3 moves depending upon the space, the axis of the rotor interlocked with the main shaft also moves, which causes a contact problem of the external diameter of the rotor with the internal diameter of the stator.
Though the clearances between the compliant frame and the guide frame at the upper and lower fitting surfaces are set up to be almost equal, it is difficult to make the clearances at the upper and lower completely equal in every scroll compressor made in mass production. Therefore, the clearances at the upper fitting surface and the lower fitting surface are different in the range of a specific allowance. In some cases, the compliant frame contacts the guide frame at either the upper fitting surface or the lower fitting surface and does not contact at the other surface during operation, which causes a change of vibrations of the axial system and a change of noises of the axial system, a performance fall based on increasing of the contact of the spiral blade top, and an increase of wear of the contact part at the blade top.
Moreover, the compliant frame 3 in operation moves in the direction of a load which the main bearing receives from the main shaft, with respect to the radial direction, by the amount of the clearance. The upper fitting surface 3c of the compliant frame 3 contacts the upper fitting surface 5a of the guide frame 5 in the load direction of the main bearing, and the lower fitting surface 3d of the compliant frame 3 contacts the lower fitting surface 5b of the guide frame 5 in the load direction of the main bearing. As the load direction of the main bearing continuously changes 360 degrees during one rotation, the compliant frame 3 performs a minute orbiting motion in the guide frame 5. However, when the compliant frame 3 itself performs a rotational movement to the guide frame, there is a problem that a loss friction is generated at the part where the compliant frame 3 contacts with the upper and lower fitting surfaces 5a and 5b of the guide frame 5 and wear is also generated. Further, there is a problem that thickness of oil film of the main bearing is reduced and a load faculty of the bearing is also decreased because the relative rotation rate of the main bearing of the compliant frame and the main shaft falls.
In order to solve these problems, a rotation prevention structure for regulating the rotation of the compliant frame is formed between the guide frame and the compliant frame in the conventional scroll compressor. This rotation prevention structure is composed of combination of a reamer pin and a reamer hole, and regulates the rotation of the compliant frame by being associated with the reamer pin inserted in the guide frame. However, as a clearance between a diameter of the reamer pin and a diameter of the reamer hole is small, the state occurs that only the reamer pin receives a gas compression load during operation, which causes a problem of a smooth minute orbiting motion being impeded within the guide frame of the compliant frame and wear of the reamer pin and the reamer hole being increased. Furthermore, when the rotation prevention mechanism composed of a plurality of combinations of a reamer pin and a reamer hole is used, the number of moving times of discontinuous contact points increases during one rotation, which causes a problem of the increase in noise. Moreover, in the state where there is a space between the reamer pin and the reamer hole of the compliant frame and there is a space between the reamer pin and the reamer hole of the guide frame, since the reamer pin inclines to the reamer hole, the reamer pin partially contacts the reamer hole in the state of slanting contact at the entrance part of the hole. Therefore, it has a problem that wear of both the reamer pin and the reamer hole is increased.
It is an object of the present invention to solve the above problems and to obtain a scroll compressor of high reliability and high efficiency with few leaks of the compression chamber. It is another object of the present invention to obtain a scroll compressor structure of high quality which can retain stable operations in the long run even in the mass-production. Furthermore, it is another object of the present invention to obtain a scroll compressor structure of high reliability in which a trouble, such as a contact of a rotation portion and a fixed portion, does not occur in the long-term use that may change the operation state.
According to one aspect of the present invention, a scroll compressor includes:
a fixed scroll provided in a hermetic container, having a spiral blade on a seat;
an orbiting scroll provided in the hermetic container, having a spiral blade on a seat, where the spiral blade of the orbiting scroll forms a compression chamber by being together with the spiral blade of the fixed scroll;
a motor provided in the hermetic container, having a rotor connected to a main shaft for rotating the orbiting scroll and a stator for giving a rotation force to the rotor;
a compliant frame provided in the hermetic container, having a thrust bearing for supporting the orbiting scroll in the axial direction, and a main bearing for supporting the main shaft in the radial direction which drives the orbiting scroll; and
a guide frame provided in the hermetic container, having an internal circumferential side contact surface and an external circumferential side contact surface, for supporting a contact surface of the compliant frame in the radial direction at the internal circumferential side contact surface which contacts with the contact surface of the compliant frame, with having a space between the contact surface of the compliant frame and the internal circumferential side contact surface of the guide frame,
wherein the space between the contact surface of the compliant frame and the internal circumferential side contact surface of the guide frame is set to be equal to or shorter than a space being a length difference between an external diameter of the rotor and an internal diameter of the stator.
According to another aspect of the present invention, a scroll compressor includes:
a fixed scroll provided in a hermetic container, having a spiral blade on a seat;
an orbiting scroll having a spiral blade on a seat, where the spiral blade of the orbiting scroll forms a compression chamber by being together with the spiral blade of the fixed scroll;
a motor provided in the hermetic container, having a stator and a rotor for giving a rotation force to a main shaft which drives the orbiting scroll;
a compliant frame provided in the hermetic container, having a thrust bearing for supporting the orbiting scroll in the axial direction, a main bearing for supporting the main shaft in the radial direction, and two contact surfaces which independently exist, that is a first fitting surface and a second fitting surface, on an external circumference of the compliant frame;
a guide frame provided in the hermetic container, having two contact surfaces which independently exist, that is a first fitting surface and a second fitting surface, on an internal circumference of the guide frame, which are formed to be contacted with each of the two contact surfaces of the compliant frame, and the guide frame supporting the compliant frame in the radial direction at the two contact surfaces;
a first space existing at a first contact part where the first fitting surface of the guide frame contacts with the first fitting surface of the compliant frame; and
a second space existing at a second contact part where the second fitting surface of the guide frame contacts with the second fitting surface of the compliant frame,
wherein at least one of the first space and the second space is set to be equal to or shorter than a space being a length difference between an external diameter of the rotor and an internal diameter of the stator.
According to another aspect of the present invention, a scroll compressor includes:
a fixed scroll provided in a hermetic container, having a spiral blade on a seat;
an orbiting scroll provided in the hermetic container, having a spiral blade on a seat, where the spiral blade of the orbiting scroll forms a compression chamber by being together with the spiral blade of the fixed scroll;
a motor provided in the hermetic container, having a rotor connected to a main shaft for rotating the orbiting scroll and a stator for giving a rotation force to the rotor;
a compliant frame provided in the hermetic container, having a thrust bearing for supporting the orbiting scroll in an axial direction and a main bearing for supporting the main shaft in a radial direction which rotates the orbiting scroll;
a guide frame provided in the hermetic container, having a contact surface which contacts with a contact surface of the compliant frame, for supporting the compliant frame by contacting the contact surface of the guide frame with the contact surface of the compliant frame; and
a reamer pin provided in the hermetic container, having two ends one of which is inserted in a reamer hole located close to the contact surface and provided in at least one of the compliant frame and the guide frame, for preventing a rotation of the compliant frame by being contacted with the other of the compliant frame and the guide frame, and the reamer pin having a space between the reamer pin and the reamer hole at a contact part where the reamer pin contacts with the reamer hole,
wherein the space between the reamer pin and the reamer hole at the contact part is set to be longer than a space between the contact surface of the guide frame and the contact surface of the compliant frame.
According to another aspect of the present invention, a scroll compressor includes:
a fixed scroll provided in a hermetic container, having a spiral blade on a seat;
an orbiting scroll having a spiral blade on a seat, where the spiral blade of the orbiting scroll forms a compression chamber by being together with the spiral blade of the fixed scroll;
a motor provided in the hermetic container, having a stator and a rotor for giving a rotation force to a main shaft which drives the orbiting scroll;
a compliant frame provided in the hermetic container, having a thrust bearing for supporting the orbiting scroll in the axial direction, a main bearing for supporting the main shaft in the radial direction, and two contact surfaces which independently exist, that is a first fitting surface and a second fitting surface, on an external circumference of the compliant frame;
a guide frame provided in the hermetic container, having two contact surfaces which independently exist, that is a first fitting surface and a second fitting surface, on an internal circumference of the guide frame, which are formed to be contacted with each of the two contact surfaces of the compliant frame, and the guide frame supporting the compliant frame in the radial direction at the two contact surfaces;
a first space existing at a first contact part where the first fitting surface of the guide frame contacts with the first fitting surface of the compliant frame;
a second space existing at a second contact part where the second fitting surface of the guide frame contacts with the second fitting surface of the compliant frame;
a reamer pin provided in the hermetic container, having two ends; and
a reamer hole provided on at least one of a guide frame plane in the radial direction between the first fitting surface and the second fitting surface of the guide frame and a compliant frame plane in the radial direction between the first fitting surface and the second fitting surface of the compliant frame,
wherein one of the two ends of the reamer pin is inserted in the reamer hole for preventing rotation of the compliant frame, and a space between the reamer pin and the reamer hole at a contact part where the reamer pin contacts with the reamer hole is set to be longer than each of the first space and the second space between the guide frame and the compliant frame.
The above-mentioned and other objects, features, and advantages of the present invention will be made more apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings.